1. Field of the Invention
The invention, in general, relates to food processing machinery of the kind equipped with feed screws for moving material from an intake, such as a hopper, through a processing station, such as choppers, knives and the like, and, more particularly, to a novel pressure barrel for a meat grinder provided with elongate channels or grooves extending longitudinally in the interior wall surface thereof for supporting, and improving the feed motion of, the material being processed.
2. The Prior Art
Conventionally, material to be processed in meat grinders and other cutting or chopping apparatus of that kind is fed into the machine through a feed opening, preferably a hopper, and is fed to a rotary cutting or knife assembly by a feed or pressure screw which is rotatably supported within, and substantially coaxially of the pressure barrel of such machine.
Pressure barrels of this general kind are disclosed, for instance, in German patent 620,312 and patent applications DE-AS 1,061,646 and DE-OS 3,245,414.
In the known apparatus, the pressure and feed screw and the barrel of the meat grinder serve to support and feed and to some extent compress the material being processed.
To this end the screw is given a special geometric configuration and is provided with flights of predetermined geometrical configurations and with additional elements, such as wedge-shaped gaps (Spaltkeile), further improving the action.
Reference is made to (East) German specification DD 287 661 which discloses a pressure barrel complementing such screws, the interior wall surface of which is specially configured by channels or grooves for purposes of further improvement in the actions referred to supra. These channels are intended to impart to the material the support necessary for feeding.
The best-known channels in such barrels are of rectangular cross-section and extend in the direction of the longitudinal axis of the barrel. However, rifled or helical channels are also utilized in pressure barrels. The edges of the channels may be rounded.
The pressure barrels are manufactured in different ways. For instance, they may be cast, welded or mechanically milled. In current manufacturing techniques the channels are formed in the same manner as the barrels, which is expensive or inefficient in terms of both material and labor.